What is Structured Text

Structured text, abbreviated as ST or STX, is one of the five languages supported by the IEC 61131-3 standard, designed for programmable logic controllers (PLCs). It is a high level language that is block structured and syntactically resembles Pascal, on which it is based. All of the languages share IEC61131 Common Elements. The variables and function calls are defined by the common elements so different languages within the IEC 61131-3 standard can be used in the same program. Complex statements and nested instructions are supported.

At first it may seem better to use a graphical programming language for PLC programming but there are pros and cons in each case. Like me, I have come to PLC from higher level programming language such as C/C++, so this fits to me better. Same general compilation process is used here. 

We shall use Visual Studio for program development and download to PLC or simulator.

Download all the necessary tools to start with Structured Text

Start downloading the necessary tools and run the first program.

This page will guide you about the tools and show how to produce the first program for Beckhoff PLC in a simulator. Please follow the page.

Learn what is timer and how it works in Structured Text with example

Timers play a vital role in automation systems. A timer is a control device that outputs a signal at a preset time. Based on the signal, the automation system can do useful work. For example, we can check every 200 MS interval if the water tank has been full or not. If the tank has been full we can stop the motor, for example, know the basics of the timer from these examples.

Learn about state machine in Structured Text

What is a state machine and how do we design in PLC. This article will describe step by step guide on how to design a state machine in a structured text programming language. We shall show how to design our main gate opening and closing as a state machine. Continue reading the article and how to develop PLC software 

This section describes about array and enumeration in Structured Text

Array Struct and enum. This section will focus on how to use an array in structured text with examples. Continue reading the tutorial.

Different data type used in Structured Text is explained here with sample

PLC data type in structured text:

Memory is a limited resource in any hardware device. This page will explain how memory works in Beckhoff PLC and how to use it in PLC software. Please follow this link for more.

Pointer, memory, addresses are explained here with sample.

Pointer and Memory in structured text:

Memory is a limited resource in any hardware device. This page will explain how memory works in Beckhoff PLC and how to use it in PLC software. Please follow this link for more.

Task, scan time, etc are explained here

PLC Task and Scan time in structured text:

Memory is a limited resource in any hardware device. This page will explain how memory works in Beckhoff PLC and how to use it in PLC software. Please follow this link for more.

What is function block? The answer is here

Function and Function block in structured text:

Memory is a limited resource in any hardware device. This page will explain how memory works in Beckhoff PLC and how to use it in PLC software. Please follow this link for more.

How to find a PLC that is  connected in the internet?

This tutorial will show how to add route to PLC program so that the PLC program can find the PLC in question. The PLC can be located on theinternet in anywhere in the world.

Difference between AMS NET ID  and IP address are here

AMS net id is a special type of identifier that is used in Beckhoff PLC to identify a PLC. It is kind of IP address.